After solder the pin headers of 2.54mm pitch on the through-holes of PCB, you can seamlessly plug it into UNO R3 controllers. It also comes with four 3mm fixed holes for you to tightly mount it.

For easy use, you can directly solder other components on the PCB through-holes to complete various prototype circuits. And you are able to stick a tiny breadboard on the prototyping area to complete various circuit experiments using jumper wires.